The effect of antibiotics on pancreatic enzyme synthesis in dogs will be investigated. Chloramphenicol, streptomycin, tetracycline, puromycin and cyclohexamide will be studied initially. Pilot experiments have indicated that pancreatic enzyme output in response to stimulation by secretion and pancreazymin is inhibited by chloramphenicol. Coincident with this inhibition of enzyme production, the total protein (measured by the biuret reaction) content of pancreatic juice increases severalfold. This unusual phenomenon is thought to result from misreading of the specifying code so that the terminate signal is not read correctly and many nonfunctional proteins result therefrom. The second phase of the experiments will be to test the effect of inhibition of pancreatic enzyme synthesis on experimental pancreatitis. Another related aspect will be the determination of the effect of the above antibiotics on amylase synthesis by the parotid gland and pepsin by the stomach.